The present invention relates to a method for manufacturing golf club heads or their prototypes.
Golf club heads and their prototypes such as clay models for the identification of golf club heads, and electro-spark machining electrodes for making metallic molds applied to the manufacturing of golf club heads are a small amount of production items based on special manufacturing specifications, and these items are manufactured by means of hand-carving or a numerically controlled computerized machine tool.
Specifically, in a conventional method for manufacturing golf club heads or their prototypes, as shown in FIG. 3, a material a, of which a golf club head or a prototype thereof is made, is firstly formed in a configuration of a rectangular parallelepiped. Next, the formed material a is set to a numerically controlled computerized milling machine (not shown), or any other similar machine, to cut this material as instructed by means of information data as inputted in a controlling system in advance. In this case, cutting is started on a surface b of the material a by using a cutting machine, such as an end mill, and is performed such that an outer frame portion c, connecting support end portions h, h and the other portions which correspond in shapes to a golf club head or a prototype thereof which is intended to be manufactured are left unmachined.
Subsequently, the material a is removed from the numerically controlled computerized milling machine, and is reversed through 180 degrees to reset it to the milling machine. Cutting is again started on the opposite side of the material, and is performed upon the other unmachined portions to form a golf club head or a prototype e thereof as illustrated in FIG. 3.
In practice, two surfaces, a horizontal surface and a vertical surface of the four outer peripheral surfaces of the material are earlier machined as reference surfaces f and g on which the computerized milling machine relies to proceed with the machining operation thereof. In a computer program which allows the milling machine to cut the material as intended, these reference surfaces f and g are also set as the starting points for the machining operation of the milling machine to both sides of the material. This prevents any variance between both sides of the material in their shapes, thereby obviating any configurational difference between both sides of a resulting golf club head or a prototype thereof.
In the foregoing conventional method for manufacturing golf club heads or their prototypes, therefore, the reference surfaces f and g of the material a are required to be pre-machined and aligned with each other before the material a is cut to form a golf club head or a prototype thereof. For this reason, the conventional manufacturing method necessitates a greater amount of time for prior processing operation. Also, the provision of the reference surfaces f and g as the starting points for the machining operation can not prevent configurational irregularity of a resulting golf club head or a prototype thereof. These are disadvantages of the conventional manufacturing method.
It is therefore an object of the present invention to provide a method for manufacturing golf club heads or their prototypes efficiently and with high accuracy, in which the foregoing disadvantages are overcome.